/*-
 * Public platform independent Near Field Communication (NFC) library examples
 * 
 * Copyright (C) 2010, Roel Verdult, Romuald Conty
 * Copyright (C) 2011, Romain Tartière, Romuald Conty
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *  1) Redistributions of source code must retain the above copyright notice,
 *  this list of conditions and the following disclaimer. 
 *  2 )Redistributions in binary form must reproduce the above copyright
 *  notice, this list of conditions and the following disclaimer in the
 *  documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * Note that this license only applies on the examples, NFC library itself is under LGPL
 *
 */

/* Emulates a NFC Forum Tag Type 4 with a NDEF message */

/*
 * This implementation was written based on information provided by the
 * following documents:
 *
 * NFC Forum Type 4 Tag Operation
 *  Technical Specification
 *  NFCForum-TS-Type-4-Tag_1.0 - 2007-03-13
 */

/* Notes & differences with nfc-emulate-tag:
 * - This example only works with PN532 because it relies on
 *   its internal handling of ISO14443-4 specificities.
 * - Thanks to this internal handling & injection of WTX frames,
 *   this example works on readers very strict on timing
 */

#include <sys/types.h>
#include <sys/stat.h>

#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>

#ifndef ENOTSUP
#define ENOTSUP		EINVAL
#endif

#include <host/nfc.h>
#include <host/nfc-emulation.h>

#include "nfc-utils.h"

static nfc_device_t *pnd;
static bool quiet_output = false;

#define SYMBOL_PARAM_fISO14443_4_PICC   0x20

typedef enum { NONE, CC_FILE, NDEF_FILE } file;

struct nfcforum_tag4_ndef_data {
	uint8_t *ndef_file;
	size_t   ndef_file_len;
};

struct nfcforum_tag4_state_machine_data {
	file     current_file;
};

uint8_t nfcforum_capability_container[] = {
	0x00, 0x0F, /* CCLEN 15 bytes */
	0x10,       /* Mapping version 1.0 */
	0x00, 0x54, /* MLe Maximum R-ADPU data size */
	/* Notes: 
	 *  - I (Romuald) don't know why Nokia 6212 Classic refuses the
	 *    NDEF message if MLe is more than 0xFD (any suggests are
	 *    welcome);
	 *  - ARYGON devices doesn't support extended frame sending,
	 *    consequently these devices can't sent more than 0xFE bytes
	 *    as APDU, so 0xFB APDU data bytes.
	 *  - I (Romuald) don't know why ARYGON device doesn't ACK when
	 *    MLe > 0x54 (ARYGON frame lenght = 0xC2 (192 bytes))
	 */
	0x00, 0xFF, /* MLc Maximum C-ADPU data size */
	0x04,       /* T field of the NDEF File-Control TLV */
	0x06,       /* L field of the NDEF File-Control TLV */
		    /* V field of the NDEF File-Control TLV */
	0xE1, 0x04, /* File identifier */
	0xFF, 0xFE, /* Maximum NDEF Size */
	0x00,       /* NDEF file read access condition */
	0x00,       /* NDEF file write access condition */
};

/* C-ADPU offsets */
#define CLA  0
#define INS  1
#define P1   2
#define P2   3
#define LC   4
#define DATA 5

#define ISO144434A_RATS 0xE0

int nfcforum_tag4_io(struct nfc_emulator *emulator,
		     const byte_t *data_in, const size_t data_in_len,
		     byte_t *data_out, const size_t data_out_len)
{
	int res = 0;
	const uint8_t ndef_capability_container[] = { 0xE1, 0x03 };
	const uint8_t ndef_file[] = { 0xE1, 0x04 };
	const uint8_t ndef_tag_application_name[] = { 0xD2, 0x76, 0x00, 0x00, 0x85, 0x01, 0x00 };
	struct nfcforum_tag4_ndef_data *ndef_data = (struct nfcforum_tag4_ndef_data *)(emulator->user_data);
	struct nfcforum_tag4_state_machine_data *state_machine_data = (struct nfcforum_tag4_state_machine_data *)(emulator->state_machine->data);
	
	if (data_in_len == 0) {
		/* No input data, nothing to do */
		return res;
	}
	
	/* Show transmitted command */
	if (!quiet_output) {
		printf("    In: ");
		print_hex(data_in, data_in_len);
	}
	
	if (data_in_len >= 4) {
		if (data_in[CLA] != 0x00)
			return -ENOTSUP;
		
#define ISO7816_SELECT         0xA4
#define ISO7816_READ_BINARY    0xB0
#define ISO7816_UPDATE_BINARY  0xD6
		
		switch(data_in[INS]) {
		case ISO7816_SELECT:
			switch (data_in[P1]) {
			case 0x00: /* Select by ID */
				if ((data_in[P2] | 0x0C) != 0x0C)
					return -ENOTSUP;
				
				if ((data_in[LC] == sizeof (ndef_capability_container)) && (0 == memcmp (ndef_capability_container, data_in + DATA, data_in[LC]))) {
					memcpy(data_out, "\x90\x00", res = 2);
					state_machine_data->current_file = CC_FILE;
				} else if ((data_in[LC] == sizeof (ndef_file)) && (0 == memcmp (ndef_file, data_in + DATA, data_in[LC]))) {
					memcpy(data_out, "\x90\x00", res = 2);
					state_machine_data->current_file = NDEF_FILE;
				} else {
					memcpy(data_out, "\x6a\x00", res = 2);
					state_machine_data->current_file = NONE;
				}
				
				break;
			case 0x04: /* Select by name */
				if (data_in[P2] != 0x00)
					return -ENOTSUP;
				
				if ((data_in[LC] == sizeof (ndef_tag_application_name)) && (0 == memcmp (ndef_tag_application_name, data_in + DATA, data_in[LC])))
					memcpy(data_out, "\x90\x00", res = 2);
				else
					memcpy(data_out, "\x6a\x82", res = 2);
				
				break;
			default:
				return -ENOTSUP;
			}
			
			break;
		case ISO7816_READ_BINARY:
			if ((size_t)(data_in[LC] + 2) > data_out_len) {
				return -ENOSPC;
			}
			switch (state_machine_data->current_file) {
			case NONE:
				memcpy(data_out, "\x6a\x82", res = 2);
				break;
			case CC_FILE:
				memcpy(data_out, nfcforum_capability_container + (data_in[P1] << 8) + data_in[P2], data_in[LC]);
				memcpy(data_out + data_in[LC], "\x90\x00", 2);
				res = data_in[LC] + 2;
				break;
			case NDEF_FILE:
				memcpy(data_out, ndef_data->ndef_file + (data_in[P1] << 8) + data_in[P2], data_in[LC]);
				memcpy(data_out + data_in[LC], "\x90\x00", 2);
				res = data_in[LC] + 2;
				break;
			}
			break;
		
		case ISO7816_UPDATE_BINARY:
			memcpy(ndef_data->ndef_file + (data_in[P1] << 8) + data_in[P2], data_in + DATA, data_in[LC]);
			if ((data_in[P1] << 8) + data_in[P2] == 0) {
				ndef_data->ndef_file_len = (ndef_data->ndef_file[0] << 8) + ndef_data->ndef_file[1] + 2;
			}
			memcpy(data_out, "\x90\x00", res = 2);
			break;
		default:
			/* Unknown */
			if (!quiet_output) {
				printf("Unknown frame, emulated target abort.\n");
			}
			res = -ENOTSUP;
		}
	} else {
		res = -ENOTSUP;
	}
	
	/* Show transmitted command */
	if (!quiet_output) {
		if (res < 0) {
			ERR("%s (%d)", strerror(-res), -res);
		} else {
			printf("    Out: ");
			print_hex(data_out, res);
		}
	}
	return res;
}

void stop_emulation(int sig)
{
	(void)sig;
	if (pnd)
		nfc_abort_command(pnd);
	else
		exit(EXIT_FAILURE);
}

size_t ndef_message_load(char *filename,
			 struct nfcforum_tag4_ndef_data *tag_data)
{
	FILE *F;
	struct stat sb;
	if (stat (filename, &sb) < 0)
		return 0;
	
	/* Check file size */
	if (sb.st_size > 0xFFFF) {
		fprintf(stderr, "file size too large '%s'", filename);
		exit(EXIT_FAILURE);
	}
	
	tag_data->ndef_file_len = sb.st_size + 2;
	
	tag_data->ndef_file[0] = (uint8_t)(sb.st_size >> 8);
	tag_data->ndef_file[1] = (uint8_t)(sb.st_size);
	
	if (!(F = fopen(filename, "r"))) {
		fprintf(stderr, "fopen (%s, \"r\")", filename);
		exit(EXIT_FAILURE);
	}
	
	if (1 != fread(tag_data->ndef_file + 2, sb.st_size, 1, F)) {
		fprintf(stderr, "Can't read from %s", filename);
		exit(EXIT_FAILURE);
	}
	
	fclose(F);
	return sb.st_size;
}

size_t ndef_message_save(char *filename,
			 struct nfcforum_tag4_ndef_data *tag_data)
{
	FILE *F;

	if (!(F= fopen(filename, "w"))) {
		fprintf(stderr, "fopen (%s, w)", filename);
		exit(EXIT_FAILURE);
	}
	
	if (1 != fwrite(tag_data->ndef_file + 2,
			tag_data->ndef_file_len - 2, 1, F)) {
		fprintf(stderr, "fwrite (%d)", (int)tag_data->ndef_file_len -2);
		exit(EXIT_FAILURE);
	}
	
	fclose(F);
	
	return tag_data->ndef_file_len - 2;
}

void usage(char *progname)
{
	fprintf(stderr, "usage: %s [infile [outfile]]\n", progname);
}

int main(int argc, char *argv[])
{
	nfc_iso14443a_info_t nai = {
		{ 0x00, 0x04 },
		0x20,
		4,
		{ 0x08, 0x00, 0xb0, 0x0b },
		4,
		{ 0x75, 0x33, 0x92, 0x03 }, /* Not used by PN532 */
	};
	nfc_target_t nt;
	uint8_t ndef_file[0xfffe] = {
		0x00, 33,
		0xd1, 0x02, 0x1c, 0x53, 0x70, 0x91, 0x01, 0x09, 0x54, 0x02,
		0x65, 0x6e, 0x4c, 0x69, 0x62, 0x6e, 0x66, 0x63, 0x51, 0x01,
		0x0b, 0x55, 0x03, 0x6c, 0x69, 0x62, 0x6e, 0x66, 0x63, 0x2e,
		0x6f, 0x72, 0x67
	};
	struct nfcforum_tag4_ndef_data nfcforum_tag4_data = {
		ndef_file,
		ndef_file[1] + 2,
	};
	struct nfcforum_tag4_state_machine_data state_machine_data = {
		NONE,
	};
	struct nfc_emulation_state_machine state_machine = {
		nfcforum_tag4_io,
		&state_machine_data,
	};
	struct nfc_emulator emulator = {
		&nt,
		&state_machine,
		&nfcforum_tag4_data,
	};

	nt.nm.nmt = NMT_ISO14443A;
	nt.nm.nbr = NBR_UNDEFINED; /* Will be updated by nfc_target_init() */
	memcpy(&nt.nti.nai, &nai, sizeof (nai));
	
	if (argc > 3) {
		usage(argv[0]);
		exit(EXIT_FAILURE);
	}
	
	/* If some file is provided load it */
	if (argc >= 2) {
		if (!ndef_message_load (argv[1], &nfcforum_tag4_data)) {
			fprintf(stderr, "Can't load NDEF file '%s'", argv[1]);
			exit(EXIT_FAILURE);
		}
	}
	
	/* Try to open the NFC reader */
	pnd = nfc_connect(NULL);
	
	if (pnd == NULL) {
		ERR("Unable to connect to NFC device");
		exit(EXIT_FAILURE);
	}
	
	signal(SIGINT, stop_emulation);
	
	printf("Connected to NFC device: %s\n", pnd->acName);
	printf("Emulating NDEF tag now, please touch it with a second NFC device\n");
	
	if (0 != nfc_emulate_target(pnd, &emulator)) {
		/* contains already nfc_target_init() call */
		nfc_perror(pnd, "nfc_emulate_target");
	}
	
	nfc_disconnect(pnd);
	
	if (argc == 3) {
		if (!(ndef_message_save(argv[2], &nfcforum_tag4_data))) {
			fprintf(stderr, "Can't save NDEF file '%s'", argv[2]);
			exit(EXIT_FAILURE);
		}
	}
	
	exit(EXIT_SUCCESS);
}
